Itamar Willner, a professor at the Institute of Chemistry at the Hebrew University, and author of a recent review of biofuel cell technology in the journal Fuel Cells, says using microbial fuel cells for the decontamination of wastewater remains “a challenge.”
“There is a tremendous difference between a demo system and upscaling to thousands of tons of wastewater, and a difference between artificially contaminated water used for laboratory testing and the real world, where you have different waste and different materials,” says Willner.
Lital Alfonta, an assistant professor in the Department of Biotechnology Engineering at Ben-Gurion University, who develops genetically engineered microbial fuel cells, says there has been growing excitement at international conferences over the progress made by Emefcy.
“They use very cheap materials that still give them the highest possible power output,” says Alfonta. “They also immensely improved the approach by stacking their electrodes, giving a much higher surface area.”
But Alfonta says that 80 percent of the energy generated by the microbes is lost in the process, because the electrons never reach the electrodes. She is researching whether the microbes can be genetically engineered to improve the efficiency of the electron transfer between the microorganism and the fuel cell’s electrode.
For the moment, Emefcy will be content if its stacks prove to be energy-neutral, with a little surplus from the industrial wastewater treatment.
“If you’re an organization that’s looking for renewable energy, don’t come to us,” says Cohen. “Go to wind. Go to solar. If you have a wastewater problem, come to us and we’ll find a way that is very cost-effective and to a certain extent it could even be an energy-positive solution.”
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